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1891.] NATURAL SCIENCES OF PHILADELPHIA. 13 

RESEAECHES UPON RESPIRATION. 
BY HENRY C. CHAPMAN, M. D. AND ALBERT P. BRU BAKER, M. D. 

No. 1. 

On the Consumption of Oxygen and the Production of 
Carbon Dioxide in Animals. 

Of all subjects of biological enquiry there is none, perhaps, that 
has attracted more attention or exceeds in importance that of the 
accurate determination of the consumption of oxygen and production 
of carbon dioxide and water in man and animals. Not only is the 
proper ventilation of our dwellings, lecture rooms, theatres, halls of 
justice, based upon such knowledge but all estimates as to the 
amount of radiant energy set free through the combustion of food, 
as determined by calori metrical experiments, are dependent upon the 
same. Passing over the early observations of Boyle, Hales, Cigna, 
Black and Priestley which showed that the air becomes so materi- 
ally modified by animals breathing it as to soon render it irrespira- 
ble unless renewed, it may be said that Lavoisier, by his classical re- 
searches, first established (1785) the modern theory of respiration 
and calorification, namely, that the carbon dioxide and water pro- 
duced during respiration and the heat thereby set free are due to the 
oxidation of the carbon and hydrogen of the food. While subse- 
quent investigations, such as those of Allen and Pepys, Milne Ed- 
wards, Despretz, Dulong, Valentin and Brunner, Boussingault and 
Barral, confirmed in the main the profound views announced by 
Lavoisier, nevertheless the differences in the results obtained were 
such as to induce Regnault and Reiset 1 to undertake an extended 
series of researches upon the respiration of different animals, more 
particularly with the view of determining the amount of oxygen con- 
sumed and carbon dioxide produced. The results of this elaborate 
investigation, it may be added, have never, in the main, been 
questioned. Inasmuch, however, as the water exhaled by an animal 
is not determined by the Regnault-Reiset apparatus, and in so far 
as known to the authors they are the only experimenters who have 
■ever had the opportunity of comparing the amount of oxygen con- 

1 Recherches Chimiques sur la Respiration des animaux des diverses classes. 
Par MM. V. Regnault et J. Reiset, Annales de Chimie et de Physique, 3me Ser., 
tome XXVI, 1849. 



14 PROCEEDINGS OF THE ACADEMY OF [1891. 

sumed as so determined directly, with the amount absorbed as deter- 
mined indirectly from the carbon dioxide and water produced, as 
obtained by means of a Voit respiration apparatus, it does not appear 
superfluous to submit the results of experimenting with the two 
kinds of respiration apparatus. 1 

Description of Apparatus. 

The Regnault-Reiset respiration apparatus in the fulfilment of 
the physical and chemical requirements incidental to the construc- 
tion of such apparatus, remains to this day unsurpassed. It consists 
essentially of the following three parts : 

A central glass bell-jar or chamber for the reception of the ani- 
mal, communicates on the one side with two glass pipettes contain- 
ing an alkaline solution for the absorption of the carbon dioxide 
produced by the animal, and on the other side with a glass pipette 
filled with oxygen to replace that absorbed by the animal in the 
bell-jar. 

The central glass bell-jar or chamber A, PI. I, tubulated above 
and having a capacity of about 47.6 litres, 2 is cemented through its 
lower open portion into the inner of two grooves with which the 
iron-plate upon which it rests is provided. The metal plate itself 
presents a central opening sufficiently large for the introduction of 
the animal into the chamber and is hermetically closed (the 
animal having been introduced) by means of a circular-metal lid, 
the latter being tightly screwed up to the under surface of the 
plate by means of bolts. The inner circular portion of the metal 
plate and upper surface of the metal lid closing the inferior opening 
of the central bell-jar are painted with red lead so as to avoid any ab- 
sorption of oxygen through oxidation of the metal. In order that 
the animal should not stand directly on the circular metal disk clos- 
ing the inferior opening of the central bell-jar (which would cool it 
too much) a movable bottom consisting of a circular wooden disk 
pierced with holes upon which the animal is placed is passed up 

1 The results obtained by Voit's respiration apparrtus will be presented in a 
subsequent communication. 

2 The absolute capacity of the jar or that of the tubes connecting it with the 
pipettes need not be determined since the investigation, is based upon a 
comparison of the composition of a given amount of the air within the jar at the 
beginning and at the end of the experiment and any extra amount of air within the 
jar as well as that in the connecting tubes can be neglected-, as they are on both 
sides of the equation. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 15 

through the inferior opening of the bell-jar. This can be easily- 
done as the wooden disk is somewhat smaller than the inferior 
opening of the jar. The circular wooden disk with the animal 
placed upon it, after being introduced through the inferior opening 
of the chamber is, slightly rotated and then lowered and comes to rest 
upon three pivots projecting inwardly over which the disk glides, 
it being sufficiently notched upon its sides for that purpose. If it be 
desired to preserve the urine and feces this can be accomplished by- 
placing a circular metal pan within the space between the under 
surface of the wooden disk and upper surface of the iron lid clos- 
ing the inferior opening of the jar into which space the excreta 
would otherwise fall. The central glass bell-jar or chamber, A PI. I, 
with a thermometer suspended within it and containing the ani- 
mal resting upon the wooden disk, the inferior opening of the 
jar being closed by the iron lid, is surrounded by water, the 
latter being held by four rectangular glass plates fitting into the 
outer of the two grooves with which the iron plate is provided. 
As it is essential that the temperature of the central bell -jar contain- 
ing the animal should be maintained as constant as possible, that 
of the water surrounding it must be maintained equally so. 

Through the upper superior portion of the central bell-jar, A PI. 
I, pass four tubes LMNO. Through the tube L the jar commun- 
icates directly with the flask P containing a solution of soda or pot- 
ash and indirectly with the pipette F containing the oxygen to be 
respired. By means of the tube M and the small mercurial manome- 
ter connected with it the pressure of the gas within the jar A can be 
determined from moment to moment. Through the two connecting 
tubes N O thejar A communicates with the two pipettes R S con- 
taining the alkaline solution for the absorption of the carbon diox- 
ide. The accessory tube T given off from the main tube O and 
leading to the large mercurial manometer enables us, as we shall see 
presently, to draw out of the jar A a sample of gas for analysis. 
The iron plate with the bell-jar A is firmly supported by a heavy 
frame- work resting upon the floor. The two glass pipettes, PI. 
I, R S, serving for the absorption of the carbon dioxide, connected 
through their lower extremities by an india-rubber tube and having 
a capacity of about three litres, are filled with a solution of caustic 
soda or potash whose weight and composition have been previously 
determined. The two glass pipettes R S are firmly attached to two 
metal supports. The supports are suspended by chains from the 



PROCEEDINGS OF THE ACADEMY OF [1891. 

beam V and with the movement of the latter alternately ascends and 
descends uniformly in a vertical manner the supports moving in a 
frame. The beam V is moved by the eccentric X which in turn is 
moved by the rotation of a number of interlocking toothed wheels W 
the movement of the latter being due to the fallof 150 kilogrammes, 
through 10 metres and regulated by a fan. The relations of the 
wheels, weight, etc. are such as to necessitate the winding up of the 
weight once only in fifteen hours. The vertical movement of the 
pipettes just described is such that as the pipette R, for example, 
ascends, the solution of soda within it passes into the pipette S which 
descends; the air in the latter freed of its carbon dioxide passing 
into the jar A while the air of A loaded with carbon dioxide passes 
into the pipette R. On the other hand, as the pipette S ascends and 
R descends, the solution of soda passing from S to R, the air of the 
pipette R, freed of its carbon-dioxide, passes back to the jar A and 
the air of the latter, loaded with carbon dioxide, passes into the 
pipette S. In order that the absorption of the carbon dioxide by 
the soda be as thorough has possible a number of glass tubes, open at 
both ends, are placed within the pipettes, the walls of these tubes 
remaining moistened with soda when the pipettes have emptied 
themselves of the alkaline solution. They present consequently a 
large absorbing surface. It will be observed that as the pipette 8 
takes air from the upper portion of the jar A and the pipette R 
from the lower portion, the play of the pipettes not only ensures 
the absorption of the carbon-dioxide in proportion as it is produced 
by the animal but keeps up a continual agitation of the air within 
the jar A which tends to maintain its composition uniform. The 
frames in which the glass pipettes move, together with the wheels 
etc. moving them, are firmly supported by a heavy metal frame- 
work resting upon the floor. The pipette, 1 F PI. I, filled with oxy- 
gen by means of the tube d, replacing that of the jar A absorbed by 
the animal, has a capacity of 19,440 c.c. between the marks b and cand 
it communicates through its upper opening and with the flask P which 
in turn communicates with the jar A and, through its lower opening 
with a vessel e which receives the liquid that flows out of the pipette 

1 In the original experiments as performed by Regnault and Reiset three 
oxygen pipettes similar to the one described above were successively used, the ex- 
periment lasting until the last pipette was exhausted. It was found, however, by 
the authors, though provided with the three pipettes, that it was easier on account 
of the connections to refill the same pipette when necessary than to substitute for 
it a second pipette previously filled. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 17 

F, when the latter is filled with oxygen, and with the tube/into which 
the liquid flows that drives the oxygen out of the pipette over into 
the jar A. The oxygen made use of by the authors was obtained by 
heating in an iron retort a mixture of chlorate of potassium and 
black oxide of manganese and passing the gas so developed through 
a solution of caustic potassa. The gas so purified and further tested 
by explosion with hydrogen, appeared to be pure. In order to intro- 
duce the oxygen into the pipette previously filled with a concen- 
trated solution of calcium chloride, little or no oxygen being ab- 
sorbed by that liquid, the stop cock on the upper tube d putting 
the oxygen reservoir in communication with the pipette and that 
on the inferior tube j conducting the fluid away, must be opened, and 
as the oxygen passes into the pipette the solution of the calcium 
chloride flows out into the vessel e. The pipette should be filled 
under a little higher pressure than that of the atmosphere and the 
gas allowed to acquire the same temperature as that of the latter. 
By allowing a little oxygen to escape and so making its elastic 
force equal to that of the atmosphere, the level of the solution of 
calcium chloride can be brought to that of the lower mark c. The 
height of the barometer and the temperature of the oxygen must 
now be noted, the latter being ascertained by means of a thermom- 
eter suspended within the pipette. 

After this somewhat detailed description of our respiration ap- 
paratus let us endeavor to describe the manner of conducting the 
experiments. 

Method of Experimentation. 

The oxygen pipette being filled under the atmospheric pressure 
H and a temperature t let V represent the capacity in litres of the 
pipette between the upper and lower marks and / the pressure of 
the aqueous vapor abandoned to the oxygen by the solution of cal- 
cium chloride, then the weight W of the oxygen delivered to the 
bell-jar supposing the pipette to be emptied to the lower mark, 1 will 
be given by the equation 

1 In order to be able, if necessary, to stop the experiment at any moment the 
pipette was graduated in litres and demilitres Owing, however, to the uncer- 
tainty as to the accuracy of the graduation incidental to the globular form and 
large size of the pipette it is undesirable to terminate the experiment before the 
pipette has emptied itself to the upper mark. 



18 PROCEEDINGS OF THE ACADEMY OF [1891. 

1 H — f 

W^l-4298 V . X L - 

1 + 0-00367 t 760 

The pressure of the vapor from the calcium chloride solution to 
be deducted from the barometric pressure, was accepted by the au- 
thors as being from 0*47 to 0*55 of the pressure of aqueous vapor at 
corresponding temperatures according as the temperatures of the 
oxygen varied from 16° C to 21° C, the experiments being made in 
winter or summer. 

The pipettes for absorbing the carbon dioxide are now weighed 
and then filled with a solution of caustic potash or soda and then 
again weighed, the difference giving the weight of the solution, the 
amount of carbon dioxide present in the soda having been previously 
determined by analysis, the method of which will be described pres- 
ently. The animal is now introduced, with food and drink if 
necessary, into the bell-jar, the walls of which have been previously 
moistened. In order to maintain the temperature of the water sur- 
rounding the bell-jar as constant as possible, the experiment should 
begin with the temperature of the water a little higher than that of 
the surrounding atmosphere, the heat given off by the animal compen- 
sating for that given off by the water. The lid closing the inferior 
opening of the jar is now screwed up and the two-way stop cocks so 
turned that the interior of the bell-jar is put in communication with 
the interior of the oxygen pipette through the intermediation of the 
flask P but cut off from the atmosphere, and the carbon dioxide pip- 
ettes put in motion through the descent of the weight. Let us 
suppose that the respiration of the animal consists simply in the con- 
sumption of oxygen and production of carbon dioxide. It is evident 
that in proportion as the oxygen of the chamber is consumed by the 
animal and the carbon dioxide produced is absorbed by the soda of 
the pipettes, the elastic force of the gas within the chamber is di- 
minished and, if the chamber communicates with the oxygen pip- 
ette, the oxygen absorbed will be at once replaced by an equivalent 
amount of oxygen, provided that the solution of calcium chloride be 
added through the tube /to that in the oxygen pipette in quantity 
sufficient to maintain the elastic force of the gas equal to that of the 
1 The number r4298=weight of 1 litre of oxygen at standard pressure and 
temperature. 
0'00367=coefficient of expansion for each deg. C. 

760.==standard barometric pressure in millimetres of mer- 
cury. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 19 

atmosphere. This successive addition of the solution of calcium 
chloride is accomplished by putting the tube of the oxygen pip- 
ette in communication with the reservoir G containing a con- 
centrated solution of calcium chloride, the level of which is main- 
tained very nearly constant by means of the three glass flasks 1, 2, 
3 filled with the same solution and which empty themselves success- 
ively as the level of the fluid in the reservoir falls, the flasks differing 
slightly from each other in the length of their necks. In proportion as 
the oxygen in the pipette becomes rarefied the liquid column in the 
tube falls and the elastic force of the air in the tube diminishes, the 
consequence of which is that the solution of calcium chloride flows 
from the reservoir into the tube and thence into the pipette. Never- 
theless the elastic force in the chamber does not remain constant 
during the time that the pipette furnishes oxygen. It diminishes in 
proportion as the pipette becomes filled with the solution of calcium 
chloride, that is if such solution was at the same level in the tube and 
the pipette at the moment that the former was cemented to the tube 
leading from the reservoir, the pressure of the air within opposing 
the flow from the reservoir 1 . As a matter of fact, however, the vari- 
ations due to the cause just mentioned may be restricted to very 
narrow limits by simply raising the level of the solution in the tube 
a few inches higher than that of the solution in the pipette before 
joining the tube to that leading from the reservoir. By so do- 
ing an excess of pressure of the gas within the chamber of about 1 
centimeter is maintained which is of advantage in compensating for 
the small amount of carbon dioxide 1 to 2 per cent always present 
in the chamber notwithstanding the constant play of the pipettes for 
the absorption of the latter. It should be mentioned, however, in this 
connection that absolute constancy of pressure can not be main- 
tained since variations in barometric pressure modify that of the 
gas within the chamber. Towards the end of the experiment, when 
there only remains about 300 cubic centimeters of oxygen in the pip- 
ette, the tubes are disconnected and the solution of calcium chloride 
poured into the tube until the solution in the pipette rises to the 
level of the upper mark when the stop cock on the tube is turned 
off. By this time there is an excess of pressure within the chamber 
of about 2 to 3 per cent and while the oxygen corresponding to this ex- 

1 That such is the case is shown by disconnecting the tubes for a moment 
after the flow from the reservoir has ceased, for in connecting them again the 
flow at once begins. 



20 PROCEEDINGS OF THE ACADEMY OF [1891. 

cess is consumed by the animal, plenty of time is afforded for making 
the temperature of the water and therefore of the chamber the same 
as at the beginning. By observing the fall of the mercury in the 
gauge the requisite number of millimetres of mercury is obtained 
which, if added to or subtracted from the observed barometric pres- 
sure, makes the final equal to the initial pressure. 1 

During this time also a sample of the gas of the chamber is drawn 
off for analysis. 

In order to draw off a sample of gas from the chamber for analy- 
sis the tube already referred to as being given off from the tube 
T is put in communication with the large mercurial manometer. 
In this case as the mercury flows out the gas flows into the manometer 
whence, as will be presently described, it is transferred for analysis to 
the Hempel burettes. It is indispensable that the sample of gas 
should be drawn from the chamber as the pipette E, ascends, inas- 
much as at that moment the gas of the chamber loaded with carbon di- 
oxide passes into that pipette and consequently into the manometer. 
If the sample was drawn as the pipette descends, the gas so obtained 
being freed of its carbon dioxide would not represent the composition 
of the gas within the chamber. The sample of gas having been 
drawn from the chamber at the moment that the pressure of the gas 
was the same as at the beginning of experiment the movement of 
the pipettes for the absorption of the carbon dioxide is stopped. 
The animal is removed and weighed together with food and excreta 
and the pipettes at once also weighed. The increase in weight of 
the pipettes at the end of the experiment as compared with their 
weight at the beginning represents both the carbon dioxide absorbed 
and the hygrometric water fixed by the concentrated solution of 
soda. The weight of the carbon dioxide contained in the solution 
of soda is then determined by analysis and deducting therefrom the 
the w r eight of the carbon dioxide that the solution contained at the 
beginning of the experiment as previously determined, the difference 
will be the weight of the carbon dioxide absorbed during the experi- 
ment by the solution of soda. This weight added to that of the car- 
bon dioxide remaining in the chamber at the end of the experi- 
ment as determined by analysis of the sample drawn from the cham- 

1 If for convenience it be necessary to terminate an experiment at any mo- 
ment, and a difference still exists between the final and initial temperatures, and 
between the final and initial pressures, the error so arising, due to the initial vol- 
ume of the gas of the chamber being thereby increased or diminished, must be 
taken into consideration in the summing up of the general results. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 21 

ber will give the total weight of the carbon dioxide produced by the 
animal. It is evident if during the experiment, oxygen has only 
been consumed and carbon dioxide only produced, the latter being as 
rapidly absorbed as produced, that the composition of the gas of the 
chamber will be the same at the end as at the beginning of the ex- 
periment. That the gas of the chamber during the experiment does 
not differ to any great extent from that of the atmosphere is shown 
not only by the analysis of the air but from the fact that the ani- 
mals do not experience any discomfort even after a much longer so- 
journ in the chamber than that to which they were subjected in the 
experiments by the authors. It should be added in this connection 
that the air of the chamber is neither altered by the food nor ex- 
creta of the animal. Let us consider now the data at our disposal 
by means of which the composition of the air of the chamber at the 
beginning and end of the experiment can be determined. The vol- 
ume of air at the beginning of the experiment is equal to that which 
is contained in the chamber, in the pipettes for the absorbing of the 
carbon dioxide, and in the connecting tubes less the volume of air 
displaced by the animal and food which are introduced into the 
the chamber. The determination of both the latter volumes when 
the density of the food can not be determined, can only be made ap- 
proximately but in taking it as equal to the volume of air displaced 
by an equal weight of water the error committed can be but slight. 
This is equally true at the end of the experiment, for apart from the 
oxygen consumed and carbon dioxide produced and nitrogen present 
being in relatively large quantities it must be remembered that by 
far the greatest part of the food consumed is still present either 
within the animal or in its excreta. Indeed the only part of the 
food actually disappearing and which diminishes its volume is that 
entering into the formation of the carbon dioxide and which must in 
any case occupy less volume than the water having the same weight 
as the carbon dioxide produced. Let V represent the volume in li- 
tres of the air of the chamber on the supposition that the animal has 
just been enclosed within the latter, H the elastic force of that air, 
at its temperature, f the pressure of the aqueous vapor at that tem- 
perature to be deducted from H, it acting in opposition to it, then 
the weight of the oxygen and nitrogen that the chamber contains at 
the beginning of the experiment can be determined by substituting 
in the following equations 



22 PROCEEDINGS OF THE ACADEMY OF [1891- 

1 H— f 

Weight of oxygen— 0*2095. l g % 4298. V. 



l+0-00367.t 760 
1 H— f 

Weight of nitrogen— 0*7905. l gr *, 2562. V. 



l+0*00367.t 760 
the values of V, H, t and f obtained by observation ; 0*2095 and 
0*7905 representing the amounts of oxygen and nitrogen per volume 
in 100 volumes of air and l* gr 4298 and l* gr 2562 the weight of a li- 
tre of oxygen and nitrogen respectively at standard pressure and tem- 
perature. At the end of the experiment H, t and f being made the 
same as at the beginning, the total volume of air then within the 
chamber will be unchanged its composition having been modified by 
the amount of carbon dioxide or other gases produced and remain- 
ing in the chamber. The weight of carbon dioxide oxygen and ni- 
trogen or other gases present in the chamber at the end of the ex- 
periment is then determined by multiplying the weight of the gases 
obtained from the sample of gas drawn from the chamber by the ra- 
tio of the volume of air of the chamber V to that of the sample v. 
Let us suppose that C, O and N represent the weight of the carbon 
dioxide oxygen and nitrogen in the sample of air drawn from the 
chamber and that ^ — M ; then CM, OM and NM will be the weight 
of the carbon dioxide, oxygen and nitrogen in the chamber at the end 
of the experiment. The weight of the carbon dioxide present in the 
chamber must be added as already mentioned to that obtained from the 
pipettes to obtain the total amount of carbon dioxide produced while 
the weight of the oxygen remaining in the chamber must be de- 
ducted from the sum of the weight of oxygen present in the cham- 
ber at the beginning of the experiment and that delivered to the 
chamber during the experiment to obtain the total weight of oxygen 
consumed. Finally the increase or diminution in the weight of the 
nitrogen within the chamber at the beginning and end of the experi- 
ment amounting to perhaps the 0*02 of a gramm the authors regard 
as being due to errors in the eudiometrical readings rather than as 
nitrogen exhaled or inhaled by the animal, the amount of nitrogen in 
the chamber present being the same at the end as at the beginning 
of the experiments. 

Method of Determining the Weight of the Carbon 

Dioxide Absorbed by the Solution of Soda 

in the Pipettes. 

The method made use of by the authors in determining the weight 

of the carbon dioxide absorbed by the soda solution in the pipettes 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 23 

was essentially that recommended by Regnault. It depends upon 
the decomposition of the sodium carbonate in the solution through 
the addition of sulphuric acid and the reabsorbing of the carbon di- 
oxide so set free by passing the latter through bulbs, etc. containing 
soda, the increase in the weight of the bulbs giving the weight of 
the carbon dioxide absorbed. The apparatus represented in F Plate 
II consists of a litre flask B into which is poured a sample of the 
soda solution from the pipettes to be analyzed. . Through the cork 
closing the flask pass three tubes, the first tube communicates with 
the U shaped tube A containing soda and pumice stone for the ab- 
sorption of the carbon dioxide in the air that passes through the ap- 
paratus at the end of the experiment. The second tube serves for 
the introduction of the sulphuric acid which should be a little less dense 
than the alkaline solution and added gradually to the latter, the 
mixture being slowly heated by gas jets to boiling. The third tube 
communicates with the narrow flask C containing concentrated sul- 
phuric acid, the latter communicating in turn with the tube D 
containing pumice stone and sulphuric acid for drying the air and 
through which the carbon dioxide developed passes on its way to 
the Liebig bulbs E containing a concentrated solution of soda and 
the tube F containing pumice stone and small pieces of caustic 
soda. The remaining tubes G and H contain pumice stone and 
concentrated sulphuric acid. The increase in weight of the three 
tubes' E F and G at the end of the experiment, the tubes having 
been previously weighed at the beginning, gives the weight of the 
carbon dioxide absorbed. To ensure accuracy in the weighing of 
the tubes E, F, G three similar tubes disposed in the same manner 
and displacing an equal volume of air should be used as counter 
weights. 

The tube H containing pumice stone and sulphuric acid serves 
to prevent the moist air depositing water in the tube G. Finally 
by means of the aspirating jar I a current of air is made to pass 
through the apparatus and of so carrying the last traces of carbon 
dioxide to the soda solution absorbing it. In order to maintain the 
tubes firmly bound together and to facilitate their connection 
and disconnection they are all clamped to a solid wooden frame- 
work by means of which they can all be removed together and in 
position when desirable. The weight of the carbon dioxide pre- 
viously existing in the soda solution placed in the pipettes at the 
beginning of the experiment for absorption of the carbon dioxide 



24 PROCEEDINGS OF THE ACADEMY OF [1891. 

produced by the animal is determined by means of the same appara- 
tus and must of course be deducted from the weight of the carbon 
dioxide absorbed, present in the soda solution at the end of the ex- 
periment. 

It has already been mentioned, that by means of the accessory 
tube T PL I given off by the tube leading from the chamber, to the 
carbon dioxide pipette R, that a sample of gas can be drawn into 
the large mercurial manometer. By so turning its three-way stop 
cock, as to let the mercury flow out, the sample so obtained is after- 
wards driven over to the absorbing or explosion apparatus for anal- 
ysis. This is accomplished by pouring mercury into the limb of 
the manometer opposite that containing the sample, the three-way 
stop cock being so turned as to put both limbs in communication 
and then of retransferring to the manometer for determination of 
volume of gases absorbed. The method made use of by the authors, 
however, in order to expedite the analysis is to draw the sample of 
gas from the chamber directly into a Hem pel graduated burette B 1 
filled with mercury, the latter, Plate III, Fig. 1, flowing out of the 
burette as the mercurial reservoir A with which the burette com- 
municates is lowered by means of the wheel work C attached to the 
solid wooden frame fastened to the table. The sample of gas so ob- 
tained reduced to standard temperature and pressure is then driven 
out of the burette B by elevating the mercurial reservoir into a 
Hempel pipettte F containing a concentrated solution of soda and 
after remaining there long enough for the absorption of any carbon 
dioxide present is driven bac*k into the graduated burette by lower- 
ing the mercurial reservoir, the diminution in volume, the latter re- 
duced to standard temperature and pressure, representing the carbon 
dioxide absorbed. The pipette for the absorption of the carbon diox- 
ide being removed, the burette is connected with one containing pyro- 
gallic acid into which the sample of gas just freed of its carbon diox- 
ide is driven by elevating the reservoir and in which it is allowed 
to remain until the oxygen present is absorbed. The sample of gas 
being then driven back into the graduated burette by lowering the 
reservoir the diminution in volume, reduced to standard temperature 
and pressure, represents the volume of oxygen absorbed. The volume 
of gas now remaining in the burette the authors regarded as consist- 
ing of nitrogen. At least the volume of residual gas in the burette was 

1 Neue Methoden fur Analyse der Gase, von Dr. VV. Hempel, Braun- 
schweig, 1880. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 25 

usually such as it ought to be on the supposition that it was nitrogen, 
and as can be shown experimentally by transferring the gas to the 
Explosion Apparatus Plate III, Fig. 2. The connection with the 
burette containing the gas is made with that limb of the apparatus 
A which has been previously filled with a solution of soda the latter 
being forced up by the mouth applied at the end of the other limb F 
and the latter then clamped. A known volume of oxygen being then 
introduced, and a sufficient volume of detonating gas developed elee- 
trolytically by means of three Daniell cells connected with the plati- 
num plates, through the binding screws H H the gaseous mixture is 
exploded by connecting a Euhmkorff apparatus with the platinum 
terminals G G. The fact of there being no diminution in the volume 
of the residual air as ascertained by transferring the gas back to the 
graduated burette proves the absence of at least hydrogen, heavy car- 
buretted hydrogen, C 2 H 4 and light carburetted hydrogen or marsh 
gas, C H 4 the gases which are the most likely to be present, the two 
former coming from the rectum of the animal the latter from its 
food. That there is no free hydrogen 1 is further shown in the absence 
of absorption on passing the residual gas through palladium. The 
following tabulated actual experiment will serve to illustrate the gen- 
eral method and order of experimentation. 

Experiment No. 17. 

Oct 29th, 8.45 P. M. 

2 Pigeons. 



BEGINNING OF EXPERIMENT. 



Weight of animal . 

" " food 
Barometer 
Temp, of Chamber . 
Pressure of Aq. Vap. 
Vol. of Gas of Chamber 

at standard temp. = 

and pressure 



LIT 

47*6 



748—15-35 



-0-567. 



0- kfL 567 

o- kiL ooo 

748 mm - 

18°C 

15°35 

LIT. 

= 42-53 



760 (1+00367*18) 



1 Were these gases present in the residual air then after explosion with 
oxygen water and carbon dioxide would be formed and retained in the pipette the 
volume of the gas being consequently diminished. It should be mentioned, how- 
ever, in this connection that it is extremely difficult whatever the kind of apparatus 
used, to determine such very small volumes of hydrogen or carburetted hydrogen 
or marsh gas as are likely to be present in the sample of gas drawn from the cham- 
ber for analysis and in neglecting to take these gases into account no very sensible 
error, at least in most instances, will be introduced into the result. 

3 



26 



PROCEEDINGS OF THE ACADEMY OF 



0-2095 1*4298 gr. 4253 



Weight of 

Oxygen in 

Chamber. 

Weight of 

Nitrogen in = 07905 1*2562 gr. 42*53 

Chamber 



[1891. 

GRAMMES. 

= 12739 
= 42-220 



Temp, of Oxygen in Pipette 


19° 


Pressure of Aq. Vap. aband. by Calcium Chloride sol. . 


7* mm -679 




GRAMMES. 


Weight of 748—7-67 




O^vrrn , n — i.^ono r . r IQ./Mft 


= 25-297 




Pipette. 760 (1+00367-19) 




Weight of Pipettes and Soda sol = 


: 7683-000 


a a 


: 6238-000 


*• Soda sol. or difference = 


- 1445-000 


Sample of Soda sol. analyzed = 140* cc 




Weight of tubes at end = 


- 258-35 


" -' beginning . . . . . — 


257*50 


Carbon dioxide absorbed or difference . = 


000-85 


Carbon dioxide in Soda sol. used . = 


8-77 


End of Experiment. 




Duration of experiment 


21 hours. 


Weight of animal = 


0-529 


" excreta ......= 


0-038 




MM. 


Barometer 


758 


Pressure in gauge ...... 


10 


Elastic force of gas in chamber .... 


748 


Temperature of chamber 


18°C 


Vol. of gas of chamber lit. 




at standard — 42*53 




temp-, and press. 




Analysis of Sample Gas. 




Barometer ........ 


762- mm -6 


Temperature of laboratory 


18°5 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 27 



;.mm.< 



Pressure of aq. vapor 15*' 

Vol. of sample of gas at observed temp, and press. = 71 cc 
Vol. of sample reduced to stand. 

temp, and press, before absorp- — 65*32 cc 

tion of carbon dioxide. 
Vol. of sample after absorption 

of carbon dioxide. = 64*40 cc 



Carbon dioxide absorbed. = 00*92 cc 

Vol. of sample after absorption 

of Oxygen. = 51*71 cc 



Oxygen absorbed. = 12*69 cc 

Composition of Gas of Chamber. 
Volume of Gas of chamber. 42530 



651 



Volume of Gas of sample. 65*32 

lit. grammes. 

0*92 651 = 0*6 1*966 = 1*179 = Carbon dioxide.-) 
12*69 651 = 8*2 1*429 = 11*789 = Oxygen. [ 

51*71 651 =~. 33*6 1*256 = 42*238 = Nitrogen. J chamben 

Composition per volume. Composition per cent. 

Carbon dioxide. 0*60 1*4 

Oxygen. 8*25 19*5 

Nitrogen. 33*62 79*1 



42*47 100*0 

GRAMMES. 

Weight of Oxygen delivered to chamber from Pipette = 25*297 
" " in chamber at beginning of exp. = 12*739 



" available 




: 


38*036 


" in chamber at end of exp. 







11*789 


" consumed by animal 


26*247 


" per hour 




= 


1*249 


a a u (i u a ~qj. 


kilo. 


= 


2*202 


Pipettes and Soda sol. 




= 


7712*000 


u 







6238*000 


Soda sol. or difference 


1474000 



28 PROCEEDINGS OF THE ACADEMY OF [1891. 

Weight of sample of Soda sol. analyzed 140 ec 

Tubes at end = 257*72 

" at beginning = 254*20 



Carbon dioxide absorbed or difference = 003*50 

1474 gr. of Soda sol. at end contained Carbon dioxide = 37*060 
1445 " " at beg. " " = 8*770 



Carbon dioxide produced by animal = 28*280 

" " absorbed by Soda sol. rem. in chamber = 1*179 



Total C0 2 produced by animal = 29*459 

Weight of Oxygen in Carbon dioxide produced = 21*424 

Weight of Oxygen in Carbon dioxide produced 21*424 

. = R e >p. Quot. = == 0-816 

Weight of Oxygen consumed 26-247 

Weight of Nitrogen in chamber at beginning — 42*22 

at end = 42*20 



00*02 
W. of C0 2 produced by animal per hour — 1*402 

W. of C0 2 produced per hour per kil. of animal = 2*472 

In order to test the accuracy of the method of experimentation 
just described by control experiments the authors burned within the 
chamber a given weight of stearic acid. 6* gr *7 of stearic acid (C 18 
H 36 2 ) when burned should theoretically produce 18*9 gr. C0 2 . 
When burned in the chamber of the respiratory apparatus, that 
amount of stearic acid actually produced 18*5 gr. of C0 2 . The loss 
0* gr 4 C0 2 or 2*1. pc. was not, therefore, greater than what might 
been have anticipated. 

The animals experimented with, rabbits, monkeys, pigeons, tur- 
tles, enjoying good health at the beginning of the experiment, did 
not appear to suffer in any way from their sojourn in the chamber 
of the respiratory apparatus. The food placed in the chamber when 
the animals had not been previously fed was in some instances not 
eaten, the animal apparently not being then hungry. The period 
of experimentation extended through the winter, spring and summer 
months of 1890. The hour of experiment selected, day or night, de- 
pended upon the convenience and the amount of time at the dis- 
posal of the experimenters. 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 29 

Experiment No. 1. 
Jan. 15th. 
Kabbit. 

Weight of animal 2* kiL 5 

Weight of food 0* kil 

Duration of experiment 7 hours, day. 

Difference between the initial and final temperature 

of the gas of the chamber .... +0°*5 C. 
Difference between the initial and final pressure of 

the gas of the chamber .... j.mm.^ 

Composition of gas of chamber at the Composition 

end of the experiment per cent 

Carbon dioxide 0*807 Carbon dioxide 2*00 

Oxygen 7*331 Oxygen 18*00 

Nitrogen 33*737 Nitrogen 80*00 



41*875 100*00 

GRAMMES. 

Weight of oxygen consumed .... 15*994 
Weight of carbon dioxide produced . . . 19*762 
Weight of oxygen contained in the carbon dioxide 14*372 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 0*898 
Weight of oxygen consumed per hour . . 2*284 
Weight of oxygen consumed per hour per kilo- 
gramme of animal ..... 0*913 
Weight of carbon dioxide produced per hour . 2*823 
Weight of carbon dioxide produced per hour per 

kilogramme of animal .... 1*129 

Experiment No. 2. 
Jan. 20th. 
Rabbit. 

Weight of animal 2. kil 4 

Weight of food, turnips 0. kil, 4 

Duration of experiment . . . 12 hrs. 45 min. night. 

Difference between the initial and final tempera- 
ture of the gas of the chamber . +0°*5 
Difference between the final and initial pressure 

of the gas of the chamber .... -|-6 mm ' 



30 



PROCEEDINGS OF THE ACADEMY OF 



[1891. 



Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*649 

Oxygen 7*755 

Nitrogen 32*333 



Composition 

per cent : 

Carbon dioxide 1*6 

Oxygen 19*0 

Nitrogen 79*4 



40*737 



Weight of oxygen consumed .... 
Weight of carbon dioxide produced 
Weight of oxygen contained in the carbon dioxide 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 
Weight of oxygen consumed per hour 
Weight of oxygen consumed per hour per kilo- 
gramme of animal 

Weight of carbon dioxide produced per hour 
Weight of carbon dioxide produced per hour per 
kilogramme of animal 

Experiment No. 3. 
Jan. 24th. 
Rabbit. 

Weight of animal 

Weight of food 

Duration of experiment 

Difference between the initial and final temperature 
of the gas of the chamber .... 

Difference between the initial and final pressure of 
the gas of the chamber ..... 
Composition of gas of chamber at the 

end of the experiment 
Carbon dioxide 0*448 Carbon dioxide 

Oxygen 8*655 Oxygen 

Nitrogen 34*036 Nitrogen 



100*0 

GRAMMES. 

31*53 
35*26 
25*65 



0*81 
2*48 

1*03 
2*76 

1*15 



2. ki, -3 

0. kil 

7*5 hrs., day. 

0°*5 C. 

4-lO mnK 

Composition 

per cent 

1*00 

20*10 

78*90 



43*139 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 



100*00 

GRAMMES. 
9*219 

10*706 
7*786 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 31 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 0*844 

Weight of oxygen consumed per hour . . . 1*229 

Weight of oxygen consumed per hour per kilo- 
gramme of animal ...... 0*534 

Weight of carbon dioxide produced per hour . 1*427 

Weight of carbon dioxide produced per hour per 

per kilogramme of animal .... 0*620 

Experiment No. 4. 
Feb. 3rd. 
Rabbit. 

Weight of animal 2* kiL 6 

Weight of food 0* kil - 

Duration of experiment 7*5 hrs., day. 

Difference between the initial and final tempera- 
ture of the gas of the chamber . . . -j-2°C. 
Difference between the initial and final pressure 

of the gas of the chamber .... i-mm-g 

Composition of gas of chamber at the Composition 

end of the experiment : per cent : 

Carbon dioxide 0*983 Carbon dioxide 2*3 

Oxygen 7*244 Oxygen 17*3 

Nitrogen 33*787 Nitrogen 80*04 



42*014 100*00 

GRAMMES. 

Weight of oxygen consumed 15*00 

Weight of carbon dioxide produced . . . 19*80 

Weight of oxygen contained in the carbon dioxide 14*40 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed 0*96 

Weight of oxygen consumed per hour . . . 2*00 
Weight of oxygen consumed per hour per kilo- 
gramme of animal ...... 0*70 

Weight of carbon dioxide produced per hour . 2*64 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 1*01 



32 PROCEEDINGS OF THE ACADEMY OF [1891. 

Experiment No. 5. 
Feb. 5th. 
Kabbit. 

Weight of animal 2* kiL 3 

Weight of food, turnips O** 11 ^ 

Duration of experiment 11 hours, day. 

Difference between the initial and final tempera- 
ture of the gas of the chamber . . . +1° C. 
Difference between the initial and final pressure of 

the gas of the chamber . • . . . . -|_4- mm -4 

Composition of gas of chamber at the Composition 

end of the experiment per cent 

Carbon dioxide 0*886 Carbon dioxide 2*1 

Oxygen 7*763 Oxygen 18*7 

Nitrogen 32*853 Nitrogen 79*2 



41*502 100-0 

GRAMMES. 

Weight of oxygen consumed 22*534 

Weight of carbon dioxide produced . . . 28*132 
Weight of oxygen contained in the carbon dioxide 20*459 
Katio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 0*907 
Weight of oxygen consumed per hour . . . 2*048 
Weight of oxygen consumed per hour per kilo- 
gramme of animal 0*890 

Weight of carbon dioxide produced per hour . 2*557 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 1*111 

Experiment No. 6. 
Feb. 1th. 
Rabbit. 

Weight of animal 2- kil 5 

Weight of food 0* kiK 

Duration of experiment 9 hrs. 

Difference between the initial and final tempera- 
ture of the chamber -j-l°C 2 

Difference between the initial and final pressure 

of the gas of the chamber .... +8 mm - 



NATURAL SCIENCES OF PHILADELPHIA. 



1891.] 

'Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*919 

Oxygen 7'849 

Nitrogen 33*963 



Carbon dioxide 

Oxygen 

Nitrogen 



33 

Composition 
per cent : 
2'15 
18-37 
79-48 



42-731 Lit. 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal 

Weight of carbon dioxide produced per hour . 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 



100-00 

GRAMMES. 

18-526 
24-010 
17-470 



0-957 
2-058 



0-823 
2-668 

1-067 



Experiment No. 7. 
Feb. 10th. 
Rabbit. 

Weight of animal . 2' kll 2 

Weight of food, turnips 0* kiL 2 

Duration of experiment .... 11 hours, night. 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure 

of the gas of the chamber 
Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*823 Carbon dioxide 

Oxygen 7'279 Oxygen 



Nitrogen 



34-956 



43-058 



Nitrogen 



0°C. 

+5 mm - 

Composition 

per cent : 

2-00 

17-00 

81-00 



Weight of oxygen consumed . 
Weight of carbon dioxide produced 



100*00 

GRAMMES. 

20-53 
24*60 



34 PROCEEDINGS OF THE ACADEMY OF [1891. 

Weight of oxygen contained in the carbon dioxide 17*90 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed 0*87 

Weight of oxygen consumed per hour . . . 1*86 
Weight of oxygen consumed per hour per kilo- 
gramme of animal 0*84 

Weight of carbon dioxide produced per hour . . 2*23 

Weight of carbon dioxide produced per hour per 

kilogramme of animal ..... 1*01 

Experiment No. 8. 
Feb. Uth. 
Rabbit. 

Weight of animal 2* kiI *5 

Weight of food, fed before experiment . 

Duration of experiment .... 1*15 hrs., night. 

Difference between the initial and final tempera- 
ture of the gas of the chamber ... 0° C* 
Difference between the initial and final pressure of 

the gas in the chamber +11" 1 " 1 - 

Composition of gas of chamber at the Composition 

end of the experiment : per cent : 

Carbon dioxide 0*889 Carbon dioxide 2*00 

Oxygen 7*946 Oxygen 19*00 

Nitrogen 32*911 Nitrogen 79*00 

41-646 100*00 

GRAMMES. 

Weight of oxygen consumed 21*58 

Weight of carbon dioxide produced . . . 26*75 

Weight of oxygen contained in the carbon dioxide 19*45 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed 0*90 

Weight of oxygen consumed per hour . . . 1*86 
Weight of oxygen consumed per hour per kilo- 
gramme of animal 0*74 

Weight of carbon dioxide produced per hour . . 2*32 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 0*92 



1891.] 



NATURAL SCIENCES OF PHILADELPHIA. 



35 



Experiment No. 9. 
Feb. 18th. 
Rabbit. 

Weight of animal 

Weight of food, turnips 

Duration, of experiment 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 

the gas of the chamber .... 
Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 1*230 Carbon dioxide 

Oxygen 6*033 Oxygen 

Nitrogen 34*165 Nitrogen 



2* kil l 

Q.kil.4 

12 hrs., night. 

+4° a 



41*428 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal 

Weight of carbon dioxide produced per hour . 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 

Experiment No. 10. 

March 11th. 

Rabbit. 

Weight of animal . 

Weight of food, turnips 

Duration of experiment 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 
the gas of the chamber 



0* m 

Composition 

per cent : 

3*000 

14*000 

83*000 

100*000 

GRAMMES. 

24*396 
29*310 
21*316 



0*873 
2*033 

0*968 
2*442 

1*162 



13 hrs. 



2* kil l 

Q.kil-4 

night. 



+ 1° C. 



+ 1" 



36 



PROCEEDINGS OF THE ACADEMY OF 



[1891. 



Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*693 

Oxygen 6*672 

Nitrogen 35*076 



Composition 
per cent : 



Carbon dioxide 

Oxygen 

Nitrogen 



42*441 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal 

Weight of carbon dioxide produced per hour . 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 



1*6 
15*7 

82*7 

100*0 

GRAMMES. 
27*21 

34*12 
24*81 



0*91 
2*09 

0*99 
2*62 

1*24 



Experiment No. 11. 

March 20th. 

Rabbit. 

Weight of animal 

Weight of food, turnips 

Duration of experiment 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 
the gas of the chamber ..... 
Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*558 Carbon dioxide 

Oxygen 6*810 Oxygen 

Nitrogen 32*592 Nitrogen 

39*960 

Weight of oxygen consumed 

Weight of carbon dioxide produced 



2* kil -4 

Q.kii.4 

13 hrs., night. 
+ 0°*5 C. 



Q.mm.Q 

Composition 

per cent : 

1*40 

17*00 

81*60 

100*00 

GRAMMES. 

27*939 

37*208 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 37 

Weight of oxygen contained in the carbon dioxide 27*242 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed 0*971 

Weight of oxygen consumed per hour . . . 2*141 

Weight of oxygen consumed per hour per kilo- 
gramme of animal 0*892 

Weight of carbon dioxide produced per hour . . 2*862 

Weight of carbon dioxide produced per hour per 

kilogramme of animal 1*192 

Experiment No. 12. 

April 2Sth. 

Rabbit. 

Weight of animal 2* kil 00 

Weight of food, turnips 0* kil 12 

Duration of experiment 9 hrs. 45 min., day. 

Difference between the initial and final tempera- 
ture, of gas in the chamber . . . . +5° C. 
Difference between the initial and final pressure of 

the gas of the chamber +3* mm '5 

Composition of gas of chamber at the Composition 

end of the experiment : per cent : 

Carbon dioxide 1*194 Carbon dioxide 2*85 

Oxygen 7*688 Oxygen 18*39 

Nitrogen 32*927 Nitrogen 78*76 



41*809 100*00 

GRAMMES. 

Weight of oxygen consumed 17*535 

Weight of carbon dioxide produced . . . 21*878 

Weight of oxygen contained in the carbon dioxide 15*911 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed 0*907 

Weight of oxygen consumed per hour . . . 1*807 
Weight of oxygen consumed per hour per kilo- 
gramme of animal ...... 0*903 

Weight of carbon dioxide produced per hour . . 2*254 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 1*127 



38 PROCEEDINGS OF THE ACADEMY OF [1891. 

Experiment No. 13. 
May 2nd. 
Babbit. 

Weight of animal l* kiL 8 

Weight of food, turnips l* kil 13 

Duration of experiment .... 11 hrs. 45 min., night. 
Difference between the initial and final tempera- 
ture of the gas of the chamber ... 0° C 
Difference between the initial and final pressure of 

the gas of the chamber _ 10 mm - 

Composition of gas of chamber at the Composition 

end of the experiment : per cent : 

Carbon dioxide 0*567 Carbon dioxide 1*40 

Oxygen 7*479 Oxygen 18*58 

Nitrogen 32*228 Nitrogen 80*02 

40*274 100*00 

GRAMMES. 

Weight of oxygen consumed 27*228 

Weight of carbon dioxide produced . . . 39*332 

Weight of oxygen contained in the carbon dioxide 28*605 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed 1*050 

Weight of oxygen consumed per hour . . . 2*326 
Weight of oxygen consumed per hour per kilo- 
gramme of animal 1*292 

Weight of carbon dioxide produced per hour . 3*361 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 1*867 

Experiment No. 14. 

April 1st. 

Monkey, Cebus capucinus. 

Weight of animal 2* kiI 00 

Weight of food, orange 0* kil 170 

Duration of experiment ...... 5 hrs., day. 

Difference between the initial and final tempera- 
ture of the gas of the chamber . . . -f-0°*5 C. 
Difference between the initial and fi ual pressure of 

the gas of the chamber ..... -f2 mra * 



NATURAL SCIENCES OF PHILADELPHIA. 



1891.] 

Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*855 

Oxygen 8*422 

Nitrogen 33*117 



39 



Composition 

per cent : 

Carbon dioxide 2*10 

Oxygen 19-80 

Nitrogen 78'10 



42-394 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Katio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal ..... 

Weight of carbon dioxide produced per hour . 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 



100-00 

GRAMMES. 

13-47 

16-389 

11-919 



0-884 
2-694 

1-347 
3-277 



1-638 



Experiment No. 15. 

April 3rd. 

Monkey, Cebus capucinus. 

Weight of animal l* kiL 50 

Weight of food, sweet potatoes .... 0* kil, 158 

Duration of experiment .... 6 hrs. 20 min., day. 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 
the gas of the chamber ..... 
Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*418 Carbon dioxide 

Oxygen 8*759 Oxygen 



Nitrogen 



33-324 
42*501 



Nitrogen 



+3°C. 

I 1 mm. 

Composition 

per cent : 

0-98 

20*61 

78-41 



Weight of oxygen consumed . 
Weight of carbon dioxide produced 



100-00 

GRAMMES. 

14-31 

18-73 



40 PROCEEDINGS OF THE ACADEMY OF [1891. 

Weight of oxygen contained in the carbon dioxide 13*62 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed 0*95 

Weight of oxygen consumed per hour . . . 2*27 

Weight of oxygen consumed per hour per kilo- 
gramme of animal ...... 1*51 

Weight of carbon dioxide produced per hour . . 2*97 

Weight of carbon dioxide produced per hour per 

kilogramme of animal ..... 1*98 

Experiment No. 16. 

May 26th. 

2 Pigeons. 

Weight of animals ,kil '57O 

Weight of food, corn 0* kll 180 

Duration of experiment .... 13 hrs. 15 min., day. 
Difference between the initial and final tempera- 
ture of the gas of the chamber . . . +0 o, 5 C. 
Difference between the initial and final pressure of 

the gas of the chamber -fl9* mm 0O 

Composition of gas of chamber at the Composition 

end of the experiment : per cent : 

Carbon dioxide 0*630 Carbon dioxide 1*42 

Oxygen 9*447 Oxygen 21*37 

Nitrogen 34*131 Nitrogen 77*21 



44*208 100*00 

GRAMMES. 

Weight of oxygen consumed 26*6804 

Weight of carbon dioxide produced . . . 32*1564 

Weight of oxygen contained in the carbon dioxide 23*1592 
Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 

of the oxygen consumed ..... 0*8680 

Weight of oxygen consumed per hour . . . 2*0218 
Weight of oxygen consumed per hour per kilo- 
gramme of animal ...... 3*5470 

Weight of carbon dioxide produced per hour . . 2*3471 
Weight of carbon dioxide produced per hour per 

kilogramme of animal 4*1 17& 



1891.] 



NATURAL SCIENCES OP PHILADELPHIA. 



41 



Experiment No. 17. 

Oct. 29th. 

2 Pigeons. 

Weight of animal 

Weight of food 

Duration of experiment 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 

the gas of the chamber .... 
Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*60 Carbon dioxide 

Oxygen 8*25 Oxygen 

Nitrogen 33*62 Nitrogen 



42-47 



Weight of oxygen consumed 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal 

Weight of carbon dioxide produced per hour . 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 

Experiment No. 18. 

April 7th. 

Turtle, Pseudemys Mobilensis. 

Weight of animal 

Weight of food, sweet potato 

Duration of experiment ...... 

Difference between the initial and final tempera- 
ture of the gas of the chamber 
Difference between the initial and final pressure of 

the gas of the chamber 

4 



0- kiL 567 
.kii. 

21 hrs. 

o°-o 

0.mm.0 

Composition 

per cent : 

1-4 

19*5 

79-1 

100-0 

GRAMMES. 

26-247 
29-459 
21*424 



0-816 
1-249 

2-202 
1-402 

2-472 



1- ML 7 

kil l 

96 hours* 

o-°a 

+ 19- mm -00 



42 



PROCEEDINGS OF THE ACADEMY OF 



Composition of gas of chamber at the 

end of the experiment : 
Carbon dioxide 0*366 

Oxygen 9*623 

Nitrogen 32*954 



[1891. 

Composition 

per cent : 

Carbon dioxide 0*85 

Oxygen 22*41 

Nitrogen 76*74 



42*943 



Weight of oxygen consumed .... 

Weight of carbon dioxide produced 

Weight of oxygen contained in the carbon dioxide 

Ratio between the weight of the oxygen contained 
in the carbon dioxide produced, and the weight 
of the oxygen consumed .... 

Weight of oxygen consumed per hour 

Weight of oxygen consumed per hour per kilo- 
gramme of animal ..... 

Weight of carbon dioxide produced per hour 

Weight of carbon dioxide produced per hour per 
kilogramme of animal .... 



100*00 

GRAMMES. 
8*612 

11*341 

8*248 



0*957 
0*088 



0*051 
0*118 

0*063 



Resume of 13 Experiments as regards the Consumption of 

Oxygen and Production of Carbon Dioxide 

by Rabbits. 





O, consumed 
per hour. 


O, consumed 
per hour ptr 
Ic.il. of animal. 


CO2, produced 
per hour. 


CO2, produced 
per hour per 
kil, of animal. 


Resp. Quot 


Exp. 


GRAMMES. 


GRAMMES. 


GRAMMES. 


GRAMMES. 




STo. 1. 


2*28 


0*91 


2*82 


1-12 


0*89 


" 2. 


2-48 


1-03 


2*76 


1*15 


0-81 


" 3. 


1-22 


0*53 


1*42 


0-62 


0*84 


" 4. 


2*00 


0*70 


2-64 


1-01 


0*96 


" 5. 


2*04 


0*89 


2*55 


1-11 


0*90 


" 6. 


2*05 


0*82 


2-66 


1-06 


0-95 


" 7. 


1-86 


0*84 


2*33 


1-01 


0-87 


" 8. 


1-86 


0-74 


2-32 


0*92 


0-90 


" 9. 


2*03 


0*96 


2*44 


1-16 


0*87 


" 10. 


2-09 


0*99 


2*62 


1-24 


0*91 


"11. 


2-14 


0*89 


2*86 


1-19 


0-97 


"12. 


1*80 


0-90 


2*25 


1*12 


0-90 


" 13. 


2*32 


1*29 


3*36 


1-86 


1-05 



Total, 26-17 



11-49 



33*03 



14*57 



11-82 



1891.] NATURAL SCIENCES OF PHILADELPHIA. 43 

26-17 11-49 33-03 

Average = = 2- gr 01 = (H r -88 = 2 gr 53 

13 13 13 
14-57 11-82 
= 1*M2 = 0-90 

13 13 

It will be observed from the above resume that the rabbit con- 
sumes upon the average 2* gr 01 of oxygen per hour and ,gr '8 of 
oxygen per hour per kilogramme of body weight and produces 2 ,gr, 5 
of carbon dioxide per hour and l ,gr l of carbon dioxide per hour 
per kilogramme of body weight, the respiration quotient or the ratio 
between the weight of the oxygen contained in the carbon dioxide pro- 
duced and the weight of the oxygen consumed amounting on the aver- 
age to 0*9. In this connection it may be mentioned that the rabbit con- 
sumes on the average the same amount of oxygen and produces the 
same amount of carbon dioxide whether the gas breathed, be the 
atmosphere as under ordinary circumstances, or pure oxygen as in 
the case of the animal being placed within the chamber of the 
respiratory apparatus. As the respiratory process in man does not 
differ from that of the rabbit, at least in its chemical aspects, there 
is no reason to suppose that any more oxygen would be consumed 
by man if breathed alone than when breathed as mixed with nitro- 
gen as obtains in the breathing of ordinary air. Notwithstanding 
that the experiments with the rabbits were performed at different 
seasons of the year, at different hours of the day or night, that food 
was or was not eaten, that in some instances the animals were more 
lively and active than in others, in a word, that the conditions in 
general varied considerably, nevertheless, it will be seen that the 
respiratory quotient varied but little in the different experiments. 

It may be mentioned that the respiratory quotient as given by Reg- 
nault & Reiset, Rauber, Colosanti, Richet, Regnard and others dif- 
fers but little from that obtained by the authors. Attention is also 
called to the fact of the consumption of oxygen and production of 
carbon dioxide being increased by the taking of food — example 6 
as compared with example 12 offers the only exception. The ani- 
mal in the former case, however, weighed more than in the latter. 

Inasmuch as in their next communication the authors propose to 
give a detailed account of their observations upon the respiration of 
monkeys as studied by means of the Voit apparatus, attention is 
simply called to the fact that the respiratory quotient (Exps. 14, 
15) differs but little, if at all, from that of the rabbit. With refer- 



44 PKOCEEDINGS OF THE ACADEMY OF [1891 . 

ence to the experiments with the pigeons (Exps. 16, 17) apart from 
the fact (of little significance) that one experiment was performed in 
May and the other in October it should be mentioned that in the first 
instance the pigeons were fed and were much more active than in the 
second which accounts for the weight of the oxygen consumed and car- 
bon dioxide produced being so much greater in the former case than 
in the latter, the respiratory quotient being 0*8. The apparatus made 
use of by the authors in the investigations just described is not well 
adapted to the study of respiration as obtained in the lower verte- 
brata, reptilia, batrachia and invertebrata. Nevertheless, the re- 
sults of an experiment (Exp. 18) with a turtle (Pseudemys mobil- 
ensis) are offered as illustrating how slowly oxygen is consumed and 
carbon dioxide is produced in such animals, the respiratory quo- 
tient, however, being the same as in the mammalia. 



PROC. ACAD. NAT. SCI. PHILA. 1891. 




CHAPMAN AND BRUB/KER ON RESPIRATION. 



PL. I. 




CHAPMAN AND BRUB/KER ON RESPIRATION. 



PROC. ACAD. NAT. SCI. PHiLA. 1891. 



PL. II. 



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PROC. ACAD. NAT. SCI. PHILA. 1891. 




CHAPMAN AND BRUBAKER ON RESPIRATION.